Investigation into Osmosis, in Potato Cylinder

Extracts from this document...

Introduction

Investigation into Osmosis, in Potato Cylinder Aim: To investigate the concentration in potato cells. Prediction: To make my prediction, I am basing it on my hypothesis. I predict, that the larger amount of sucrose, the very least amount of water will remain in the cell, as there isn't enough water for osmosis. Osmosis ( a diffusion of water) will occur across a semi permeable membrane when there is a difference between the water concentrations on the two sides of the membrane. Knowing this, I water will flow through them making the cells turgid or plasmolyse if water flows out of them and all this will change the volume. Hypothesis: From the Oxford biology textbook, pages 21-23 and the encyclopaedia. This is the information I had obtained and also using the information from my preliminary test. If the concentration is great then the potato cylinder will contract by shrivelling up and if the concentration is lower than that level, it will probably expand. ...read more.

Middle

This made me chose my accurate range for this work, by changing the concentration amount accurately to 0.0M - 0.5M. Fair Test: Variable Why does it need to be controlled? How will I control it ? Core Borer To get the same width / diameter of the cylinder It will be controlled by using the same borer. Length of Potato So the same amount of liquid can / could be absorbed. This could be done by cutting the lengths the same, 3cm. Amount of Liquid To which potato absorbs more of the concentrate By using the same measuring cylinder and measuring it accurately Length of Time To have a set time for the concentrate to be absorbed My time will be set to start 18/3/2002 at 2:20pm for 20hrs and 40min, it will be checked at 9:00am on the 19/3/2002. Potatoes So the results don't become a mixture of wrinkled potato and a smooth new potato. ...read more.

Conclusion

The concentrate was measured out in the same measuring cylinder of 10ml and was then poured into the 15 boiling tubes, we did this by molarity using sucrose and distilled water. We used the accurate ranges from the preliminary tests for making up our concentrate(as we know the more of the sucrose, more the cells will become plasmolysed). 3. The cylinders were then placed into the solution in the boiling tube in 10 seconds as it was impossible for them to be put into the tube at the same time. 4. The tubes were left for 20hrs and 40mins. We left the tubes un covered as the room temperature would probably stay the same and pressure, but these factors would maybe affect the osmosis, but the size, volume and surface area would be the same. 5. When it comes to check on the cylinder lengths, using the same ruler to cut them down to size was also used to measure the length. ?? ?? ?? ?? Inderjit Maan B10 Science Coursework Mr Niklau 18/3/2002 ...read more.